Reverse flow disk drive and head suspension for same

ABSTRACT

A head suspension for a reverse flow disk drive. The head suspension includes a load beam having a mounting region at a proximal end, a rigid region at a distal end and a spring region between the mounting region and the rigid region. A flexure is mounted on the distal end of the rigid region. A slider is mounted on the flexure. The slider has a proximal end closest to the proximal end of the load beam. One or more read/write heads located on the proximal end of the slider. The head suspension can include one or more of an airflow attenuator, micro-actuators, and/or an inverted gimbal.

[0001] The present application claims the benefit of U.S. ProvisionalPatent Application Ser. Nos. 60/205,344 filed May 18, 2000 entitledMeans of Reducing Windage Generated Off-Tracking by Reversing thePlatters Spin Direction; 60/217,789 filed Jul. 12, 2000 entitled Flexurefor Reducing Windage Generated in Reverse Flow Drive, and 60/221,758filed Jul. 31, 2000 entitled Suspension/E-Block Based Downstream Air Damfor Reverse Flow Drive (Dam Located Downstream of HGA).

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a reverse flow disk in a datastorage device and to a head suspension for supporting a read/write headin a reverse flow disk. Airflow induced vibration is reduced over thecurrent state of the art by rotating the disks so that the read/writeheads are upstream of the rigid region of the head suspension relativeto the air flowing with the disks. Certain flexures and electricalconnections enable conventional read/write heads to be used in thepresent reverse flow disk drive. Additional reductions in airflowinduced vibrations can be achieved with the placement of downstreamattenuators.

[0004] 2. Description of the Related Art

[0005] Most personal computer systems today employ direct access storagedevices (DASD) or rigid disk drives for data storage. A conventionaldisk drive 20, such as shown in FIG. 1, contains a plurality ofmagnetically coated recording disks 26 mounted on the spindle forrotation in a direction 24 so that flexure 42 is downstream of load beam40 relative to airflow 23. The disks 26 could alternatively rotate in adirection opposite to 24 with the airflow 23 also moving in the oppositedirection from shown in FIG. 1, provided that head suspension 32 isoriented so that the flexure 42 is downstream of the load beam 40.

[0006] The disks 26 contain a plurality of disk features. As usedherein, “disk features” refers to discrete magnetic or opticalproperties of the coated disks. The number of disks 26 and thecomposition of their magnetic material coating determine, in part, thedata storage capacity of the disk drive 20. Positioned adjacent theperipheries of the rotating disks 26 is an E-block 28 having a pluralityof actuator arms 30 each supporting one or more head suspensions 32 thatextend in cantilever fashion over the disks 26.

[0007]FIG. 2 shows the head suspension 32 used to support and properlyorient a head slider 34 over the rotating disks 26 of FIG. 1 in moredetail. A variety of head suspensions can be used for this purpose, suchas disclosed in U.S. Pat. No. 5,920,444 (Heeren et al.). Head suspension32 has a longitudinal axis 36, and is comprised of a base plate 38, aload beam 40, and a flexure 42. Base plate 38 is mounted to a proximalend 44 of load beam 40, and is used to attach head suspension 32 to theactuator 30 in the disk drive 20. Slider 34 is mounted to flexure 42,and as the disk 26 in the storage device 20 rotates beneath head slider34, an air bearing is generated between slider 34 and the rotating disk26 that creates a lift force on head slider 34. This lift force iscounteracted by a spring force generated by the load beam 40 of headsuspension 32, thereby positioning the slider 34 at an alignment abovethe disk referred to as the “fly height.” Flexure 42 provides thecompliance necessary to allow head slider 34 to gimbal in response tosmall variations in the air bearing generated by the rotating disk.

[0008] Load beam 40 of head suspension 32 has an actuator mountingregion 46 at proximal end 44, a load region 48 adjacent to distal end50, a resilient spring region 52 positioned adjacent actuator mountingregion 46, and a rigid region 54 that extends between spring region 52and load region 48. Resilient spring region 52 generates a predeterminedspring force that counteracts the lift force of the air bearing actingon head slider 34. Toward this end, spring region 52 can include anaperture 53 to control the spring force generated by spring region 52.Rigid region 54 transfers the spring force to load region 48 of loadbeam 40. A load point dimple (not shown) is formed in load region 48,and contacts flexure 42 to transfer the spring force generated by springregion 52 to flexure 42 and head slider 34. A load point dimple canalternatively be formed in flexure 42 to extend toward and contact withload region 48 of load beam 40.

[0009] The flexure 42 is formed as a separate component and is mountedto load beam 40 near the distal end 50. Flexure 42 includes a gimbalregion 56 and a load beam mounting region 58. Load beam mounting region58 overlaps and is mounted to a portion of rigid region 54 usingconventional means, such as spot welds. Gimbal region 56 of flexure 42provides the necessary compliance to allow head slider 34 to gimbal inboth pitch and roll directions about load point dimple in response tofluctuations in the air bearing generated by the rotating disk. Towardthis end, gimbal region 56 includes a cantilever beam 60 having a slidermounting surface to which head slider 34 is attached. Cantilever beam 60is attached to cross piece 62, which is connected at each end to firstand second arms 64 a and 64 b of flexure 42. Cantilever beam 60 isresiliently movable in both pitch and roll directions with respect tothe remainder of flexure 42, and thereby allows head slider 34 togimbal. Load point dimple (when formed in load region 48) contacts thesurface opposite the slider mounting surface of cantilever beam 60 totransfer the spring force generated by spring region 52 of load beam 40to head slider 34, and further to provide a point about which headslider 34 and cantilever beam 60 can gimbal. In dynamic storage devicesoptical or magnetic read/write heads 66 are supported on a trailing edge68 of the slider 34. The trailing edge 68 is defined in relation to thedirection 24 that the disk 26 rotates.

[0010] A continued trend for greater areal density and faster datatransfer rates for rigid disk drives place more demand on suspensionwindage performance. One way to increase areal density is to increasethe number of tracks per inch (TPI), which requires a reduction in trackmisregistration. The suspension's contribution to off-track due towindage excitation must be maintained within ever-tightening trackmisregistration requirements. One approach to increase the data transferrate and reduce latency is to increase the disk RPM. Higher disk RPM cannegatively impact suspension windage performance because of increasedwind energy. For example, if you spin two identical drives at differentRPM, the higher RPM drive is going to create a greater amount of windenergy due to increased disk velocity and therefore higher trackmisregistration. To satisfy the continuing trends of rigid disk drives,tighter track misregistration will require suspensions that exhibit lessoff-track due to windage when exposed to increase levels of windageenergy due to increasing disk speeds.

[0011] Interactions that determine the suspension's windage-drivenoff-track can be generalized into three separate variables: sourceenergy, energy extraction and the transfer function. Windage off-trackoccurs due to source energy that originates from fast spinning disks.Turbulent effects of the E-block and other drive features alsocontribute to source energy. One way to describe the magnitude andinfluence of source energy is with the Bernoulli Equation. Assume thatfor any given system, off-track is related to dynamic pressure:$\left. {SourceEnergy}\Rightarrow{Pressure}_{Dynamic} \right. = {\frac{1}{2} \cdot {FluidDensity} \cdot ({Velocity})^{2}}$

[0012] Fluid density and fluid velocity are the two primary factors,with velocity having a squared effect. For a given suspension, anincrease in dynamic pressure will result in an increase in windageoff-track (an increase in source energy with all else remainingconstant). In terms of windage, the ideal case is to have disks spinningas slowly as possible, thus creating minimal turbulence.

[0013] The second variable is the suspension's efficiency to extractenergy from the source. Different suspension designs extract differentamounts of energy from a given source, depending on part length, surfacearea, rail height, headlift feature, etc. The third variable is thesuspension's transfer function. After a certain amount of wind energy isabsorbed into the suspension, the transfer function dictates how ittranslates to slider off-track. For all suspension modes, the transferfunction dictates a given ratio of output per input. The ideal goal isto have output minimized as much as possible by having the ratio asclose to zero as possible.

[0014] Turning back to FIG. 1, rotation of the disks 26 creates airflow23 within the disk drive 20. The actuator arms 30 and the E-block 28channel the airflow 23 toward the head suspension 32. Air flow 23encounters the E-block 28 and the actuator arms 30 first, with the headsuspensions 32 and flexure 42 located downstream of this obstruction.Consequently, the head suspension 32 is located in the E-block's wake.Any turbulent flow generated by the E-block 28 and/or actuator arm 30can propagate downstream and strike the head suspension 32. The E-block28 and actuator arms 30 act as funnels to direct more airflow 23 towardthe head suspension 32. According to the conservation of mass flow, asthe cross-sectional area of the flow region becomes restricted, thefluid density and/or the velocity must increase to account for thesmaller cross-sectional area. Increases in these values increase themagnitude of the dynamic pressure acting on the head suspension 32, thusadding to the windage-induced suspension off-track.

SUMMARY OF THE INVENTION

[0015] The present invention relates to a head suspension for a reverseflow disk drive. The head suspension includes a load beam having amounting region at a proximal end, a rigid region at a distal end and aspring region between the mounting region and the rigid region. Aflexure is mounted on the distal end of the rigid region. A slider ismounted on the flexure. The slider has a proximal end closest to theproximal end of the load beam, wherein the spring region, the rigidregion, the flexure and the slider comprise an active portion. One ormore read/write heads are located on the proximal end of the slider.

[0016] In another embodiment, the head suspension includes a load beamhaving a mounting region at a proximal end, a rigid region at a distalend and a spring region between the mounting region and the rigidregion. A flexure is mounted on the distal end of the rigid region. Aslider is mounted on the flexure. The slider has one or more read/writeheads, wherein the spring region, the rigid region, the flexure and theslider comprise an active portion. The head suspension includes one ormore micro-actuators adapted to move the slider in response to atracking control signal.

[0017] In yet another embodiment, the head suspension includes a loadbeam having a mounting region at a proximal end, a rigid region at adistal end and a spring region between the mounting region and the rigidregion. A flexure is mounted on the distal end of the rigid region. Aslider is mounted on the flexure. The slider has one or more read/writeheads, wherein the spring region, the rigid region, the flexure and theslider comprise an active portion. The head suspension includes one ormore airflow attenuators located downstream from the active portion.

[0018] The flexure can optionally be an inverted gimbal. Any of theembodiments disclosed herein can include one or more airflow attenuatorslocated downstream from the active portion. The airflow attenuators aretypically located on one of the mounting region or an inactive portionof an unamount arm. The airflow attenuator are optionally integrallyformed with the mounting region. The airflow attenuators can optionallyextend along one or more of the side, the top or the bottom of the headsuspension. In one embodiment, the airflow attenuators include a shapeadapted to create a region of reduced airflow velocity proximate theflexure and/or the active portion.

[0019] The present invention is also directed to a reverse flow diskdrive. The reverse flow disk drive includes one or more disks and one ormore of the head suspensions discussed herein. One or more airflowattenuators can be located downstream from the active portion on theactuator arms.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0020] Further objects and features of the present invention are setforth in the following detailed description of the preferred embodimentsof the invention and in the drawing figures wherein:

[0021]FIG. 1 is a schematic illustration of a prior art disk drive.

[0022]FIG. 2 is a perspective view of a prior art head suspension.

[0023]FIG. 3 is a schematic illustration of a reverse flow disk drive inaccordance with the present invention.

[0024]FIG. 3A is a schematic illustration of an alternate reverse flowdisk drive including an unamount arm in accordance with the presentinvention.

[0025]FIG. 4 is a perspective view of a head suspension for use in areverse flow disk drive in accordance with the present invention.

[0026]FIG. 5 is a bottom view of a flexure in accordance with thepresent invention.

[0027]FIG. 6 is a perspective view of an alternate head suspension inaccordance with the present invention.

[0028]FIG. 7 is a bottom view of an alternate flexure in accordance withthe present invention.

[0029]FIG. 8 is a top view of a load beam and flexure in accordance withthe present invention.

[0030]FIG. 9 is a bottom view of a flexure with an inverted gimbal foruse in a reverse flow disk drive in accordance with the presentinvention.

[0031]FIG. 10 is a perspective view of a reverse flow disk drive with amicro-actuated head suspension in accordance with the present invention.

[0032]FIG. 11 is a schematic illustration of a reverse flow disk driveincluding an attenuator in accordance with the present invention.

[0033] FIGS. 12-14 illustrate various embodiments of head suspensionassemblies including attenuators in accordance with the presentinvention.

[0034]FIGS. 15a-15 b are graphical data showing windage off-track for afirst head suspension in a conventional disk drive.

[0035]FIGS. 15c-15 d are graphical data showing windage off-track for asecond head suspension in a conventional disk drive.

[0036]FIGS. 16a-16 b are graphical data showing windage off-track in areverse flow disk drive using the head suspension evaluated in FIG.15a-15 b.

[0037]FIGS. 16c-16 d are graphical data showing windage off-track in areverse flow disk drive using the head suspension evaluated in FIG.15c-15 d.

[0038]FIG. 17a is graphical data showing windage off-track in a reverseflow disk drive without a downstream attenuator.

[0039]FIG. 17b is graphical data showing windage off-track in thereverse flow disk drive evaluated in FIG. 17a with a downstreamattenuator.

DETAILED DESCRIPTION OF THE INVENTION

[0040]FIG. 3 illustrates a reverse flow disk drive 70 including amagnetic disk stack 72 and a head stack assembly 74 with headsuspensions 76 in accordance with the present invention. As used herein,“reverse flow disk drive” refers to a disk drive in which the disk isrotated in a direction that causes disk features to pass the read/writehead(s) before passing the suspension arm. In a reverse flow disk drive,the most distal end of the head suspension leads into the airflow causedby disk rotation.

[0041] Disk stack 72 includes one or more spaced disks 78 (two are shownin FIG. 3) mounted to a spindle for rotation by a drive motor. Headstack assembly (or E-block) 74 includes a plurality of actuator arms 80having proximal ends mounted to actuator shaft 82. The proximal ends ofhead suspension assemblies 76 are mounted to the distal ends of actuatorarms 80 in a conventional manner such as by swage boss 84. Flexure 88 islocated at distal end of rigid portion 91 of load beam 94. Slider 86with a magnetic read/write head is mounted to the flexure 88 of eachhead suspension assembly 76. Spring region 96 biases the slider 86against the disk 78. The actuator arms 80 are spaced from one another byspacers 90 in such a manner that the suspensions 76 mounted theretoextend between disks 78 to position the sliders 86 and magnetic headsadjacent to the disk surfaces.

[0042] The disks 78 rotate in a direction 92 at several thousandrevolutions per minute (RPM) while the disk drive is turned on.Consequently, active portion 99 of the head suspension 76 leads into theairflow 98. As used herein, “active portion” refers to the spring regionand all portions of the head suspension distal thereto, including therigid region and the flexure.

[0043] In the reverse flow disk drive 70 illustrated in FIG. 3, theflexure 88 and the slider 86 are located in a more laminar, lowervelocity region of the airflow 98 than in the standard flow conditions(see FIG. 1). The airflow 98 progresses down the load beam 94 to thespring region 96, and finally passes the actuator arms 80. The air flow98 has its greatest energy immediately after passing the actuator arms80. After passing the actuator arms 80, the airflow 98 has approximatelythree-quarters of a turn of the disk 78 for turbulence to dissipatebefore it again strikes the active portion 99 of the head suspension 76.The present reverse flow disk drive 70 does not expose the flexure 88and slider 86 to the high energy airflow that is found immediatelydownstream of the actuator arms 80, as occurs in a conventional diskdrive (see FIG. 1). As used herein, “downstream” is relative to theairflow generated by rotation of the disks in the disk drive.

[0044]FIG. 3A illustrates an alternate reverse flow disk drive 70A inwhich the actuator arms 80 and the head suspension assembly 76 arereplaced with a single structure referred to as an unamount arm 76A. Theunamount arm 76A is typically attached directly to actuator column 93A.Portion 80A of the unamount arm 76A comprises a fairly rigid inactiveportion of the head suspension 76 that is resistant to airflow inducedvibrations. Spring region 96A, rigid region 91A and flexure 88A comprisethe active portion 99A in the head suspension assembly 76A of FIG. 3A.The disks 78A rotate on spindle 95A in the direction 92A so that theairflow 98A first encounters flexure 88A and then progresses down therigid region 91A, the spring region 96A and the portion 80A. The activeportion 99A leads into the airflow 98A, as discussed above. In oneembodiment, inactive portion 80A includes an airflow attenuator 97A,discussed in detail below.

[0045] FIGS. 4-9 are directed to various head gimbal assemblies suitablefor use in the present reverse flow disk drive.

[0046]FIG. 4 shows one embodiment of the head suspension 132 used tosupport and properly orient a head slider 134 over the rotating disk 126(see FIG. 3). Head suspension 132 has a longitudinal axis 136, and iscomprised of a base plate 138, a load beam 140, and a flexure 142. Baseplate 138 is mounted to a proximal end 144 of load beam 140, and is usedto attach mounting region 146 of head suspension 132 to the actuator 130in the disk drive 120. Slider 134 is mounted to flexure 142, and as thedisk 126 in the storage device 120 rotates beneath head slider 134, anair bearing is generated between slider 134 and the rotating disk 126that creates a lift force on head slider 134. This lift force iscounteracted by a spring force generated by the load beam 140 of headsuspension 132, thereby positioning the slider 134 at an alignment abovethe disk referred to as the “fly height.” Flexure 142 provides thecompliance necessary to allow head slider 134 to gimbal in response tosmall variations in the air bearing generated by the rotating disk 126.

[0047] Flexure 142 includes a gimbal region 156 and a load beam mountingregion 158. Load beam mounting region 158 overlaps and is mounted to aportion of rigid region 154 using conventional means, such as spotwelds. Gimbal region 156 of flexure 142 provides the necessarycompliance to allow head slider 134 to gimbal in both pitch and rolldirections about load point dimple in response to fluctuations in theair bearing generated by the rotating disk.

[0048] Toward this end, gimbal region 156 includes a cantilever beam 160having a slider mounting surface to which head slider 134 is attached.Cantilever beam 160 is attached to cross piece 162, which is connectedat each end to first and second arms 164 a and 164 b of flexure 142.Cantilever beam 160 is resiliently movable in both pitch and rolldirections with respect to the remainder of flexure 142, and therebyallows head slider 134 to gimbal. Load point dimple (when formed in loadregion 148) contacts the surface opposite the slider mounting surface ofcantilever beam 160 to transfer the spring force generated by springregion 152 of load beam 140 to head slider 134, and further to provide apoint about which head slider 134 and cantilever beam 160 can gimbal.

[0049] Optical or magnetic read/write heads 166 are preferably supportedon a trailing edge 168 of the slider 134. The trailing or downstreamedge 168 is defined in relation to the airflow 98 illustrated in FIG. 3.Since the disks 72 rotate in the opposite direction than illustrated inFIG. 1, the trailing edge 168 is the edge of the slider 134 closest tothe proximal end 144. Locating the read/write heads 166 at the trailingedge 168 of the slider 134 maintains the flying characteristics of thehead suspension 132 when used in a reverse flow disk drive. In oneembodiment, slider 134 is a conventional slider rotated 180 degrees sothat the read/write heads 166 are oriented as shown.

[0050]FIG. 5 is a bottom view of the flexure 142 of FIG. 4 with theslider 134 removed. Electrical wires, traces or integrated leads 174 a,174 b, 174 c, 174 d (referred to collectively as “174”) extend along thefirst and second arms 164 a, 164 b and the cross piece 162 to theproximal edge 170 of the slider mounting surface 147. Various othersuitable trace configurations are disclosed in U.S. Pat. No. 6,046,888(Krinke et al.). Slider mounting surface 147 is attached to the crosspiece 162 in a cantilevered fashion so that gap 176 is formed aroundseveral sides of the surface 147, including along the proximal edge 170.Consequently, contact pads 172 a, 172 b, 172 c, 172 d are locatedadjacent to the proximal edge 170 for electrical coupling with theread/write heads 166 (see FIG. 4).

[0051] In one embodiment, the traces 174 a, 174 b, 174 c, 174 d comprisemultiple segments. Segments 175 of the traces 174 may be a simpleelectrical conductor or some other device, such as a micro-actuator (seefor example U.S. Pat. Nos. 5,994,159, 5,923,798, 5,912,094 and6,046,888), a sensor, an integrated circuit chip, such as apre-amplifier, or a variety of other devices. The electrical traces usedon any of the embodiments disclosed herein can be formed using a varietyof techniques, including wireless or integrated leads made by anadditive deposition process, a trace carrier laminate, or a wirelessflexure, such as disclosed in U.S. Pat. No. 5,982,584.

[0052]FIG. 6 is a bottom view of the flexure 142 with a modified slider134 a and modified traces 174 a, 174 b, 174 c, 174 d (referred tocollectively as “174”) in accordance with the present invention. Thetraces 174 terminate at the distal edge 171 of the slider mountingsurface (see FIG. 5). Contact pads 172 a, 172 b, 172 c, 172 d (referredto collectively as “172”) are located near the distal edge 171. Themodified slider 134 a includes integral electrical conductors 173 thatelectrically couple the contact pads 172 to the read/write heads 166near the proximal edge 170. The electrical conductors 173 can beinternal or external to the slider 134 a.

[0053]FIG. 7 is a bottom view of an alternate flexure 242 in whichelectrical traces 274 a, 274 b, 274 c, 274 d extend across gap 276between the slider mounting surface 247 and the first and second arms264 a, 264 b to the proximal edge 270 of the slider mounting surface247. Contact pads 272 a, 272 b, 272 c, 272 d are located adjacent to theproximal edge 270 for electrical coupling with the read/write heads 166oriented toward the proximal end 273 (see FIG. 4).

[0054]FIG. 8 is a top view of another alternate flexure 342 in which theelectric traces 374 extend along the load beam 340. A hole or via 378 isformed in the load beam 340 and the slider mounting surface 347 on thegimbal 342 so that distal ends 373 of the traces 374 can be electricallycoupled with the slider. Consequently, no integrated leads need beformed on the flexure 342.

[0055]FIG. 9 is a bottom view of an inverted gimbal 280 for use with thepresent reverse flow disk drive. A pair of outer arms 282 are attachedto a distal cross piece 284 at distal end 283 that connects to a pair ofinner arms 286. The inner arms 286 connect to a proximal cross piece 288adjacent proximal end 289 of the inverted gimbal 280. The proximal crosspiece 288 is connected to the cantilever beam 290 and a slider mountingsurface 292. The traces 294 are routed along the outer arms 282, thedistal cross piece 284, the inner arms 286 and the proximal cross piece288 to the slider mounting surface 292. As used herein, “invertedgimbal” refers to a gimbal with a cantilever beam located on theproximal side of the slider mounting surface. In one embodiment, distalcross piece 284 is welded to the load beam (not shown) on the distalside of the gimbal 280 to minimize the risk of buckling. The invertedgimbal 280 permits the use of conventional sliders with the read/writeheads oriented toward the proximal end 289 (see FIG. 4).

[0056]FIG. 10 illustrates a reverse flow disk drive 500 with amicro-actuated head suspension assembly 502. In the illustratedembodiment, the micro-actuator comprises motors 504 and 506. The motors504, 506 can each be biased with a voltage so that active portion 524 isdeflected along tracking axis 510 or 512 in response to a trackingcontrol signal. In head suspension assemblies with a micro-actuator, theactive portion 524 typically refers to flexure 508, rigid region 526 andspring region 528. The micro-actuator can be piezoelectric,electro-strictive, magnetic field generating coils,micro-electro-mechanical devices (MEMS),micro-optical-electro-mechanical devices (MOEMS), or the like. Sincepiezoelectric elements or electro-strictive elements do not use magneticfield generating coils, use of such elements reduces the likelihood ofinterference between microactuator tracking signals and read/writeprocesses and are generally preferred. Other suitable head suspensionincluding a micro-actuator are disclosed in U.S. Pat. No. 6,046,888(Krinke et al.).

[0057] In a conventional disk drive, the disk 514 rotate in a direction516. The kinetic energy of the resulting airflow 518 is increased whenit encounters actuator arms 505 and the micro-actuated suspensionassembly 502. The higher energy and higher velocity airflow 518increases airflow induced vibrations to the active portion 524. In thepresent reverse flow disk drive 500, the disks 514 rotate in a direction520 so that the active portion 524 leads into the resulting airflow 522,with a significant reduction in airflow induced vibration, as discussedherein.

[0058] Further reductions in suspension windage can be achieved with theaddition of downstream airflow attenuators. The downstream airflowattenuators work by reducing the velocity of the air in the region wherethe head suspension is located. The airflow attenuators work by creatinga zone with higher static pressure (lower velocity) air around the headsuspension. Oncoming air is diverted by the zone of higher staticpressure. The reduction in airflow velocity causes an overall reductionin dynamic pressure.

[0059]FIG. 11 illustrates a reverse flow disk drive 400 incorporating adownstream airflow attenuator 402 downstream of active portion 420, andin particular, downstream of head gimbal assembly 414. The attenuator402 can be located on the actuator arms 404 or on inactive portion 422of the head suspension assembly 406. The inactive portion 422 of thehead suspension assembly 406 is the portion downstream of the activeportion 420, typically the mounting region and/or the base plate 416. Inone embodiment, the attenuator 402 is located at the interface betweenthe base plate 416 and the actuator arm 404.

[0060] As used herein, “attenuator” refers to a structure locateddownstream from the active portion whose primary function is to reducethe velocity and kinetic energy of the airflow in a region adjacent tothe active portion. While the head gimbal assembly in a reverse flowdisk drive redirects a portion of the airflow, the amount of airflowthat is redirected is significantly less than that redirected by anattenuator. Attenuators also extend beyond the boundaries of the headsuspension assembly and/or the actuator arm(s). For some embodiments,the effective surface area of an attenuator can be measured as afunction of the length of the head suspension measured from the proximaledge of the mounting region to the distal end of the flexure. Forexample, an attenuator with a surface area of about 10.0 millimeters²divided by a head suspension with a length of about 8.5 millimetersproduces a ratio of 1.18 millimeters.

[0061] In the embodiment of FIG. 11, the attenuator 402 has a leadingedge with an effective surface area that encounters the airflow 408greater than the effective surface area of the leading edge 415 of thehead gimbal assembly 414. As used herein, “leading edge” refers to theentire front edge of a particular structure that directly encounters theairflow.

[0062] In the illustrated embodiment, the attenuator 402 extends on bothside of the head suspension assembly 406. In an alternate embodiment,the attenuator 402 may extend along one side, the top and/or the bottomof the head suspension assembly 406. In yet another embodiment, the diskdrive 400 may include an attenuator on both the actuator arms 404 andthe head suspension assembly 406. Due to the nature of the reverse flowdisk drive 400, attenuators 402 can be located on the actuator arms 404,the E-block, an unamount arm (see FIG. 3A), and/or the base plate (seeFIGS. 12-14).

[0063] As the airflow 408 travels around the attenuator 402, the airflowin the region 412 immediately upstream of the attenuator 402 has a lowervelocity and a lower kinetic energy. The reduced velocity is due to theattenuator 402 restricting the airflow 408, thus partially shielding thehead suspension 406 from the airflow 408 and promoting more of theairflow 408 to choose a path of least resistance on either side of theattenuator 402. What remains of the airflow 408 in the region upstreamof the attenuator 402 has a lower velocity and lower kinetic energy. Asa result, the head gimbal assembly 414 is located in a region of reducedvelocity and energy. Use of attenuators in reverse flow disk drives canfurther reduce airflow induced vibration of the head suspension.

[0064] As used herein, “airflow velocity” and “airflow kinetic energy”are preferably measured in a region away from the head suspension 406and actuator arms 419. Regions of reduced velocity and regions ofreduced kinetic energy near the head gimbal are measured relative to theairflow velocity and airflow kinetic energy immediately downstream ofthe base plate and/or the actuator arms.

[0065] The attenuators of the present invention can be designed andmanufactured in a variety of ways and shapes. The attenuator can be ofvarious sizes and geometry designed to focus the optimal effect in theregion of the flexure and slider. The size, shape, location and numberof attenuators can vary with the application. One possible trade-off ispower consumption. The larger the attenuator, the more drag that may beput on the drive motor, requiring more energy to maintain disk rotation.

[0066]FIG. 12 is a schematic illustration of a head suspension assembly440 in accordance with the present invention. A pair of attenuators 444,446 are formed integrally from the same material forming the load beamand positioned on both sides of the load beam stiffener 448. Partialetch lines can be formed to facilitate bending of the attenuators 444,446. Although the attenuators 444, 446 are located on both sides of theload beam stiffener 448, an attenuator on only one side of the stiffener448 is possible. In the embodiment of FIG. 12, the base plate 442 andthe attenuators 444, 446 comprise the inactive portion 458. The inactiveportion is located downstream from active portion 456 in a reverse flowdisk drive (see FIG. 3). Alternatively, the attenuators 444, 446 can beformed integrally with the base plate 442 or as separate component(s)attached to the base plate 442 by spot welding, adhesive, or a varietyof other techniques.

[0067] The attenuators 444, 446 optionally extend downward below thelevel of the load beam stiffener 448. The attenuators 444, 446 are alsoswept forward toward the head gimbal assembly 450. The shape of theattenuators 444, 446 can be modified to alter the shape of the region452 of reduced velocity and reduced kinetic energy created by airflow454. For some applications, two or more attenuators may be usedsimultaneously. In another embodiment, the attenuator 402 can beintegrally formed with the actuator arms (or e-block).

[0068]FIG. 13 is a perspective view of an alternate head suspension 460in accordance with the present invention. Base plate 462 includes anintegrally formed attenuator 464 having a pair of cutouts 466 on eitherside of the load beam stiffener 468. When the attenuator 464 is foldedin the upright position illustrated in FIG. 13, portions 470 of theattenuator 464 extend below the load beam stiffener 468. Again, theattenuator 464 can be formed as a separate component and attached to thehead suspension assembly 460 using suitable techniques. In theembodiment of FIG. 13, attenuator 464 creates a region 476 of reducedvelocity and reduced kinetic energy of airflow 478 around active portion472 of the head suspension 460. The shape of the region 476 is shownschematically and can very with the shape, size and location of theattenuator 464.

[0069]FIG. 14 illustrates an alternate head suspension assembly 490having an attenuator 494 formed on an edge of reverse base plate 492.Thickness 496 of the base plate 492 times the width 498 of the baseplate 492 comprise the effective surface area of the attenuator 494. Noadditional forming or stamping processes are required. When the baseplate 492 is attached to the head suspension assembly 490, theattenuator 494 is positioned downstream of active portion 497 to engageairflow 499, as discussed above.

EXAMPLE 1

[0070] FIGS. 15A-D illustrate off-track movement generated by airflowinduced vibration within a conventional disk drive. FIGS. 16A-Dillustrate off-track movement generated by the same head suspensionsevaluated in FIGS. 15A-D in a reverse flow disk drive. FIGS. 15A, 15B,16A, and 16B illustrate the performance of a Mag 5e micro-actuated headsuspensions, available from Hutchinson Technology located in Hutchinson,Minn., at about 10,000 revolutions per minute and about 15,000revolutions per minute. FIGS. 15C, 15D, 16C, and 16D illustrate theperformance of a 4230 TSA head suspensions, also available fromHutchinson Technology located in Hutchinson, Minn., at about 10,000revolutions per minute and about 15,000 revolutions per minute. Thegraph indicates the windage generated off track in nanometers.

[0071] The z-height indicated on the graphs is the distance between theactuator mount and the disk surface. The sliders were turned about 180degrees so that the read/write heads were on the downstream side of theslider relative to the airflow, as generally indicated in FIG. 4. Thehead suspension setup included a gap of about 60 millimeters between thecenter of rotation of the disks and the center of rotation of theactuator arms. The distance from the center of rotation of the actuatorarms to the slider was about 52 millimeters. The distance between theslider and the center of rotation of the disks was about 30 millimeters.There was about a 2.4 millimeter gap between the two adjacent disks. Thetest was performed with the suspensions between the two spinning disks.

[0072] As illustrated in FIG. 16A, at about 10,000 revolutions perminute the Mag 5e micro-actuated head suspension experienced about a 68%reduction in windage induced vibration than the vibration experienced ina conventional disk drive as illustrated in FIG. 15A. As illustrated inFIG. 16B, at about 15,000 revolutions per minute the Mag 5e headsuspension experienced about a 67% reduction in windage inducedvibration than the vibration experienced in a conventional disk drive asillustrated in FIG. 15B.

[0073] Similarly, as illustrated in FIG. 16C, at about 10,000revolutions per minute the 4230 TSA head suspension experienced about a55% reduction in windage induced vibration than the vibrationexperienced in a conventional disk drive as illustrated in FIG. 15C. Asillustrated in FIG. 16D, at about 15,000 revolutions per minute the 4230TSA head suspension experienced about a 61% reduction in windage inducedvibration than the vibration experienced in a conventional disk drive asillustrated in FIG. 15D.

[0074] The micro-actuated Mag 5e head suspension experienced a greaterreduction in windage induced vibration than the non-actuated 4230 TSAhead suspension. The difference in reduction is believed to be due toundesirable aerodynamic features on the Mag 5e micro-actuated headsuspension.

EXAMPLE 2

[0075]FIG. 17A illustrates off-track movement generated by airflowinduced vibration in a reverse flow disk drive without an airflowattenuator. FIG. 17B illustrates off-track movement generated by airflowinduced vibration in a reverse flow disk drive with an airflowattenuator. The head suspension assembly was a Mag 5e available fromHutchinson Technology located in Hutchinson, Minn. The disk drive wasoperated at about 10,000 revolutions per minute. The airflow attenuatorwas generally as indicated in FIG. 12 and had an effective surface areaof 10 millimeters². The graph indicates the windage generated off trackin nanometers.

[0076] As illustrated in FIG. 17B, at about 15,000 revolutions perminute the head suspension with the airflow attenuator experienced abouta 33% reduction in windage induced vibration than the vibrationexperienced by the head suspension without the airflow attenuator.

[0077] All of the patents and patent applications disclosed herein,including those set forth in the Background of the Invention, are herebyincorporated by reference. With regard to the foregoing description, itis to be understood that changes may be made in detail, withoutdeparting from the scope of the present invention. For example, thepresent reverse airflow disk drive can be used with any combination ofairflow attenuators, micro-actuators on the head suspension, and orbackward flexures. It is intended that the specification and depictedaspects be considered exemplary only, with a true scope and spirit ofthe invention being indicated by the broad meaning of the followingclaims.

What is claimed is:
 1. A head suspension for a reverse flow disk drive,the head suspension comprising: a load beam having a mounting region ata proximal end, a rigid region at a distal end and a spring regionbetween the mounting region and the rigid region; a flexure mounted onthe distal end of the rigid region; a slider mounted on the flexure, theslider having a proximal end closest to the proximal end of the loadbeam, wherein the spring region, the rigid region, the flexure and theslider comprise an active portion; and one or more read/write headslocated on the proximal end of the slider.
 2. The head suspension ofclaim 1 wherein the flexure comprises an inverted gimbal including agimbal distal end adjacent to the distal end of the rigid region and agimbal proximal end, the inverted gimbal comprising: a pair of outerarms extending from the gimbal proximal end to a distal cross pieceproximate the gimbal distal end; a pair of inner arms extending from thedistal cross piece to a proximal cross piece proximate the gimbalproximal end; and a cantilever beam connecting the proximal cross pieceto a slider mounting region.
 3. The head suspension of claim 1comprising: a via extending through the rigid region and the flexureproximate a rear surface of the slider; and electrical conductorsextending through the via and electrically coupled to the slider.
 4. Thehead suspension of claim 1 comprising one or more airflow attenuatorslocated downstream from the active portion.
 5. The head suspension ofclaim 1 comprising at least one airflow attenuator located on one of themounting region or an inactive portion of an unamount arm.
 6. The headsuspension of claim 1 comprising at least one airflow attenuatorintegrally formed with the mounting region.
 7. The head suspension ofclaim 1 comprising one or more airflow attenuators extending along oneor more of the side, the top or the bottom of the head suspension. 8.The head suspension of claim 1 comprising one or more airflowattenuators including a shape adapted to create a region of reducedairflow velocity proximate the flexure.
 9. The head suspension of claim1 comprising one or more airflow attenuators including a shape adaptedto create a region of reduced airflow velocity proximate the activeportion.
 10. The head suspension of claim 1 comprising one or moremicro-actuators.
 11. The head suspension of claim 1 comprisingelectrical traces including one of a micro-actuator, a sensor or anintegrated circuit.
 12. The head suspension of claim 11 wherein aportion of the electrical traces are integral with the slider and extendfrom a distal end of the slider to the proximal end of the slider. 13.The head suspension of claim 1 wherein the flexure comprises: acantilevered slider mounting surface having a free end extending towardthe proximal end of the load beam; a gap between the free end and theflexure; one or more electrical traces spanning the gap; and contactpads on the slider mounting surface near the free end electricallycoupled with the electrical traces spanning the gap.
 14. A headsuspension for a reverse flow disk drive, the head suspensioncomprising: a load beam having a mounting region at a proximal end, arigid region at a distal end and a spring region between the mountingregion and the rigid region; a flexure mounted on the distal end of therigid region; a slider mounted on the flexure having one or moreread/write heads, wherein the spring region, the rigid region, theflexure and the slider comprise an active portion; and one or moremicro-actuators adapted to move the slider in response to a trackingcontrol signal.
 15. The head suspension of claim 14 comprising: a viaextending through the rigid region and the flexure proximate a rearsurface of the slider; and electrical conductors extending through thevia and electrically coupled to the slider.
 16. The head suspension ofclaim 14 comprising one or more airflow attenuators located downstreamfrom the active portion.
 17. The head suspension of claim 14 comprisingat least one airflow attenuator located on one of the mounting region oran inactive portion of an unamount arm.
 18. The head suspension of claim14 comprising at least one airflow attenuator integrally formed with themounting region.
 19. The head suspension of claim 14 comprising one ormore airflow attenuators extending along one or more of the side, thetop or the bottom of the head suspension.
 20. The head suspension ofclaim 14 comprising one or more airflow attenuators including a shapeadapted to create a region of reduced airflow velocity proximate theflexure.
 21. The head suspension of claim 14 comprising one or moreairflow attenuators including a shape adapted to create a region ofreduced airflow velocity proximate the active portion.
 22. A headsuspension for a reverse flow disk drive, the head suspensioncomprising: a load beam having a mounting region at a proximal end, arigid region at a distal end and a spring region between the mountingregion and the rigid region; a flexure mounted on the distal end of therigid region; a slider having one or more read/write heads mounted onthe flexure, wherein the spring region, the rigid region, the flexureand the slider comprise an active portion; and one or more airflowattenuators located downstream from the active portion.
 23. The headsuspension of claim 22 wherein the flexure comprises an inverted gimbal.24. The head suspension of claim 22 comprising at least one airflowattenuator located on one of the mounting region or an inactive portionof an unamount arm.
 25. The head suspension of claim 22 comprising atleast one airflow attenuator attached to the mounting region.
 26. Thehead suspension of claim 22 comprising at least one airflow attenuatorintegrally formed with the mounting region.
 27. The head suspension ofclaim 22 comprising one or more airflow attenuators extending along oneor more of the side, the top or the bottom of the head suspension. 28.The head suspension of claim 22 comprising one or more airflowattenuators including a shape adapted to create a region of reducedairflow velocity proximate the flexure.
 29. The head suspension of claim22 comprising one or more airflow attenuators including a shape adaptedto create a region of reduced airflow velocity proximate the activeportion.
 30. The head suspension of claim 22 comprising one or moremicro-actuators.
 31. The head suspension of claim 22 comprisingelectrical traces including one of a micro-actuator, a sensor or anintegrated circuit.
 32. A reverse flow disk drive, comprising: one ormore disks; one or more head suspensions comprising; a load beam havinga mounting region at a proximal end, a rigid region at a distal end anda spring region between the mounting region and the rigid region; aflexure mounted on the distal end of the rigid region; a slider mountedon the flexure, the slider having a proximal end closest to the proximalend of the load beam, wherein the spring region, the rigid region, theflexure and the slider comprise an active portion; and one or moreread/write heads located on the proximal end of the slider.
 33. Thereverse flow disk drive of claim 32 comprising one or more airflowattenuators located downstream from the active portion.
 34. The reverseflow disk drive of claim 32 comprising at least one airflow attenuatorlocated on one of the mounting region or an inactive portion of anunamount arm.
 35. The reverse flow disk drive of claim 32 comprising atleast one airflow attenuator located on an actuator arm.
 36. The reverseflow disk drive of claim 32 comprising one or more airflow attenuatorsextending along one or more of the side, the top or the bottom of thehead suspension.
 37. The reverse flow disk drive of claim 32 comprisingone or more airflow attenuators including a shape adapted to create aregion of reduced airflow velocity proximate the flexure.
 38. Thereverse flow disk drive of claim 32 comprising one or more airflowattenuators including a shape adapted to create a region of reducedairflow velocity proximate the active portion.
 39. The reverse flow diskdrive of claim 32 comprising one or more micro-actuators.
 40. Thereverse flow disk drive of claim 32 comprising electrical tracesincluding one of a micro-actuator, a sensor or an integrated circuit.41. The reverse flow disk drive of claim 40 wherein a portion of theelectrical traces are integral with the slider and extend from a distalend of the slider to the proximal end of the slider.
 42. A reverse flowdisk drive, comprising: one or more disks; one or more head suspensionscomprising: a load beam having a mounting region at a proximal end, arigid region at a distal end and a spring region between the mountingregion and the rigid region; a flexure mounted on the distal end of therigid region; a slider mounted on the flexure having one or moreread/write heads, wherein the spring region, the rigid region, theflexure and the slider comprise an active portion; and one or moremicro-actuators adapted to move the slider in response to a trackingcontrol signal.
 43. A reverse flow disk drive, comprising: one or moredisks; one or more head suspensions comprising: a load beam having amounting region at a proximal end, a rigid region at a distal end and aspring region between the mounting region and the rigid region; aflexure mounted on the distal end of the rigid region; a slider havingone or more read/write heads mounted on the flexure, wherein the springregion, the rigid region, the flexure and the slider comprise an activeportion; and one or more airflow attenuators located downstream from theactive portion.